It’s time to take a closer look at what you’re swiping under your arms. Here’s why: You’re wearing it 24/7—even if you shower daily. The effects of roll-on, stick, and spray antiperspirant lasted through tests of stress, physical exertion, and heat a full 48 hours after application, according to a recent German study published in the International Journal of Cosmetic Science.

How is that even possible? The active ingredients don’t just sit on top of your skin. Unlike deodorants, which simply mask odor, antiperspirants stop sweat at its source.